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![James Almer](/assets/img/avatar_default.png)
* commit '83548fe894cdb455cc127f754d09905b6d23c173': lavf: fix usage of AVIOContext.seekable Merged-by: James Almer <jamrial@gmail.com>
161 lines
4.6 KiB
C
161 lines
4.6 KiB
C
/*
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* Tele-typewriter demuxer
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* Copyright (c) 2010 Peter Ross <pross@xvid.org>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* Tele-typewriter demuxer
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*/
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#include "libavutil/intreadwrite.h"
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#include "libavutil/avstring.h"
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#include "libavutil/log.h"
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#include "libavutil/dict.h"
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#include "libavutil/opt.h"
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#include "libavutil/parseutils.h"
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#include "avformat.h"
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#include "internal.h"
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#include "sauce.h"
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typedef struct TtyDemuxContext {
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AVClass *class;
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int chars_per_frame;
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uint64_t fsize; /**< file size less metadata buffer */
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int width, height; /**< Set by a private option. */
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AVRational framerate; /**< Set by a private option. */
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} TtyDemuxContext;
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/**
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* Parse EFI header
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*/
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static int efi_read(AVFormatContext *avctx, uint64_t start_pos)
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{
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TtyDemuxContext *s = avctx->priv_data;
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AVIOContext *pb = avctx->pb;
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char buf[37];
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int len;
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avio_seek(pb, start_pos, SEEK_SET);
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if (avio_r8(pb) != 0x1A)
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return -1;
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#define GET_EFI_META(name,size) \
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len = avio_r8(pb); \
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if (len < 1 || len > size) \
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return -1; \
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if (avio_read(pb, buf, size) == size) { \
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buf[len] = 0; \
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av_dict_set(&avctx->metadata, name, buf, 0); \
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}
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GET_EFI_META("filename", 12)
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GET_EFI_META("title", 36)
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s->fsize = start_pos;
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return 0;
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}
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static int read_header(AVFormatContext *avctx)
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{
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TtyDemuxContext *s = avctx->priv_data;
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int ret = 0;
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AVStream *st = avformat_new_stream(avctx, NULL);
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if (!st) {
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ret = AVERROR(ENOMEM);
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goto fail;
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}
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st->codecpar->codec_tag = 0;
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st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
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st->codecpar->codec_id = AV_CODEC_ID_ANSI;
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st->codecpar->width = s->width;
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st->codecpar->height = s->height;
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avpriv_set_pts_info(st, 60, s->framerate.den, s->framerate.num);
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st->avg_frame_rate = s->framerate;
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/* simulate tty display speed */
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s->chars_per_frame = FFMAX(av_q2d(st->time_base)*s->chars_per_frame, 1);
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if (avctx->pb->seekable & AVIO_SEEKABLE_NORMAL) {
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s->fsize = avio_size(avctx->pb);
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st->duration = (s->fsize + s->chars_per_frame - 1) / s->chars_per_frame;
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if (ff_sauce_read(avctx, &s->fsize, 0, 0) < 0)
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efi_read(avctx, s->fsize - 51);
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avio_seek(avctx->pb, 0, SEEK_SET);
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}
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fail:
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return ret;
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}
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static int read_packet(AVFormatContext *avctx, AVPacket *pkt)
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{
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TtyDemuxContext *s = avctx->priv_data;
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int n;
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if (avio_feof(avctx->pb))
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return AVERROR_EOF;
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n = s->chars_per_frame;
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if (s->fsize) {
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// ignore metadata buffer
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uint64_t p = avio_tell(avctx->pb);
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if (p == s->fsize)
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return AVERROR_EOF;
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if (p + s->chars_per_frame > s->fsize)
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n = s->fsize - p;
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}
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pkt->size = av_get_packet(avctx->pb, pkt, n);
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if (pkt->size < 0)
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return pkt->size;
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pkt->flags |= AV_PKT_FLAG_KEY;
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return 0;
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}
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#define OFFSET(x) offsetof(TtyDemuxContext, x)
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#define DEC AV_OPT_FLAG_DECODING_PARAM
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static const AVOption options[] = {
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{ "chars_per_frame", "", offsetof(TtyDemuxContext, chars_per_frame), AV_OPT_TYPE_INT, {.i64 = 6000}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM},
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{ "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
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{ "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, DEC },
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{ NULL },
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};
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static const AVClass tty_demuxer_class = {
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.class_name = "TTY demuxer",
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.item_name = av_default_item_name,
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.option = options,
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.version = LIBAVUTIL_VERSION_INT,
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};
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AVInputFormat ff_tty_demuxer = {
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.name = "tty",
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.long_name = NULL_IF_CONFIG_SMALL("Tele-typewriter"),
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.priv_data_size = sizeof(TtyDemuxContext),
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.read_header = read_header,
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.read_packet = read_packet,
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.extensions = "ans,art,asc,diz,ice,nfo,txt,vt",
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.priv_class = &tty_demuxer_class,
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};
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